The present invention relates to the combination of multiple suspending gang nail plates on a gypsum board panel, the panel being mounted to a demountable partition wall utilizing a framework of vertical studs and horizontal bar members for suspending the panel to form a wall.
In recent years, removable partition walls have been widely used in buildings. In general, these walls involve mounting channel-like tracks on the floor and ceiling, installing vertical, channel-like metal studs in laterally spaced relationship between the runners, and securing gypsum board (sheetrock) panels to the studs. However, this technique is labor intensive because it requires that several operations be conducted on the joints between panels, e.g., they must be filled, taped and concealed with battens, to produce a neat, finished appearance.
A battenless system is described in U.S. Pat. No. 3,550,338, but the system described in that patent is characterized by a number of disadvantages and limitations, most importantly, that the metal strips used in the system must be of substantial length and width. This requirement arises from a shortcoming which is characteristic of gypsum board, namely that the bond between the board filling and the paper layer is frequently weaker in certain portion of tne panels than others. By providing long, wide strips, the system described in that patent ensures that at least portions of each strip will be attached to properly bonded material. Such strips are, however, relatively expensive, and thus contribute significantly to the cost of the system. Further, the strips, and the hooks and cut-outs of the system, must be precisely manufactured and positioned so that adjacent panels will be drawn into closely abutting relation. This precise manufacturing and assembly likewise adds to the cost of the system. Another limitation of this type of system is that considerable stress is placed on a relatively narrow portion of the stud due to the weight of the panels. This concentration of the weight leads to the sagging and weakening of the lateral stability of the wall. However, the wall usually is not reinforced to overcome this tendency because of the additional cost.
Another system is described in U.S. Pat. No. 3,948,011. That patent describes a system which includes gang nail plates which are said to be relatively inexpensive and easily attached to the back of a gypsum board panel for assembly into a wall system including horizontal channel members. Such a system is said in that patent to be competitive, price wise, with those systems on the market which use only vertical studs. This system is, however, likewise characterized by a number of disadvantages and limitations, as evidenced by the improvement patents, U.S. Pat. Nos. 4,128,979, 4,245,448, 4,394,808, 4,448,004, and 4,693,047 directed to various components of that same system that were ostensibly designed to solve the various problems encountered in erecting the system described in U.S. Pat. No. 3,948,011 (the "'011 patent").
Another limitation of the system described in that patent is not apparent from a description of the content of the specification of that patent. Specifically, that patent is, on information and belief, presently licensed exclusively to the National Gypsum Company's Gold Bond Building Products Division. Difficulties in dealing with the Gold Bond Building Products distribution system, and the fact that (in spite of the indication in the specification of the patent that the system is competitive, price-wise, with other systems on the market) the system has an installed price which is actually higher than the price at which permanently mounted dry wall can be installed, have provided the motivation for the present invention, the object of which is to provide a system which actually does have the cost and other advantages touted in the specification of the '011 patent for that system.
Another object of the present invention is to provide a demountable wall system in which the space between gypsum board panels is completely open to allow the flexibility of routing wires, cables, conduit or other utilities vertically within the wall cavity without obstructions, a significant advantage in a business or other environment in which computers, telephones, and other electronic equipment must be networked or linked together, an object which is not achievable with the system described in the '011 patent.
Another object of the present invention is to provide a demountable wall system which is assembled quickly and which requires minimal use of hand tools, using gravity and the weight of the components thereof to pull adjacent gypsum board panels into alignment with each other.
Another object of the present invention is to provide a demountable wall system which can be manufactured at low cost due to the minimal number of cuts and bends required to work the metal comprising each component of the system.
Another object of the present invention is to provide a demountable wall system having increased lateral stability over those wall systems which are currently available.
Still another object of the present invention is to provide a demountable wall system having the capability of supporting the gypsum board panels thereof from either the edges of the panels or from the center using a horizontal member and a suspension clip resting thereon.
Another object of the present invention is to provide a demountable wall system with improved fire code ratings.
Another object of the present invention is to provide a demountable wall system characterized by its flexibility of use. In other words, in certain instances, it is not necessary to support the gypsum board panel from behind to prevent flexing of the finished wall. For instance, at the end of a wall, there may be, for example, just an eight inch span between adjacent studs instead of the twenty-four (or whatever spacing is chosen) inch spacing between the centers of adjacent studs. In such instances, there is no need for the horizontal member extending between studs behind the panel. Nevertheless, the horizontal members must be used because there is no other way to support the gypsum board panel in the case of, for instance, the system described in the '011 patent. Further, not being a standard length, the horizontal members described in that patent must be cut to the desired length on the job site, adding to construction time and increasing wastage.
Other objects, and the advantages of the present invention, will be made clear by the following detailed description of one demountable wall system which is constructed in accordance with the present invention.